A GNU C Library security update has been released for Ubuntu Linux 16.04 ESM.

USN-5699-1: GNU C Library vulnerabilities

==========================================================================
Ubuntu Security Notice USN-5699-1
October 25, 2022

glibc vulnerabilities
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 16.04 ESM

Summary:

Several security issues were fixed in GNU C Library.

Software Description:
- glibc: GNU C Library

Details:

Jan Engelhardt, Tavis Ormandy, and others discovered that the GNU C Library iconv feature incorrectly handled certain input sequences. An attacker could possibly use this issue to cause the GNU C Library to hang or crash, resulting in a denial of service. (CVE-2021-3326)

It was discovered that the GNU C Library nscd daemon incorrectly handled
certain netgroup lookups. An attacker could possibly use this issue to
cause the GNU C Library to crash, resulting in a denial of service.
(CVE-2021-35942)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 16.04 ESM:
libc6 2.23-0ubuntu11.3+esm2

After a standard system update you need to reboot your computer to make
all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-5699-1
CVE-2021-3326, CVE-2021-35942